Preheat the oven to 220°C fan (425°F).
Pat the chicken dry thoroughly with kitchen paper and place it breast-side up in a roasting dish.
Prepare the garlic oil: in a small bowl, mix the olive oil with finely chopped rosemary, a pinch of salt, and black pepper.
Rub the garlic oil all over the chicken, making sure to coat the breast, legs, and wings evenly.
Tie the legs together with kitchen string and tuck the wing tips underneath the bird.
Roast for 10 minutes, then reduce the oven temperature to 180°C fan (350°F).
Continue roasting for 1 hour 10–15 minutes, basting once or twice with the pan juices.
The chicken is ready when the juices run clear at the thigh joint or the internal temperature reaches 75°C (165°F).
Remove the chicken from the oven and transfer it to a cooling rack to rest for 15 minutes.
Carefully pour the juices from the roasting tin into a bowl or jug. You can thicken them into a gravy if you like, but they’re delicious just as they are.
